On a collision course
- By Dan Verton, George I. Seffers
- Jul 03, 2000
An upcoming test will require the national missile defense system to strike
down a Minuteman II intercontinental ballistic missile carrying a single
warhead target and a single decoy. The Minuteman will be launched from Vandenburg
Air Force Base, Calif. Twenty minutes later, an interceptor missile carrying
a prototype "kill vehicle" will be launched from Kwajalein atoll in the
Pacific Ocean and should home in on and clash directly with the target warhead.
Intercepting an incoming missile begins with the space-based warning
system, which detects a booster launch. The Defense Support Program is already
in place, and the Pentagon is upgrading that with a system known as Space
Based Infrared System-High, which has greater sensitivity and greater ability
to predict trajectories.
The space-based detection system passes the information through the
command and control system to the early-warning radars, which have already
been deployed in various places around the globe. The radars track the incoming
missiles, providing preliminary data on where the incoming missile is headed
and other information necessary for the intercept.
That information is passed to the so-called X-band radars, which are
small frequency radars that one member of Congress says can detect a golf
ball high over Seattle from hundreds of miles away. It is primarily the
X-band radars that distinguish harmless decoys from destructive warheads.
Once the warheads are pinpointed, the ground-based interceptor is launched.
It consists of a booster and the so-called kill vehicle, which, if necessary,
can receive updated or corrected flight information from the X-band radar
while in flight. The kill vehicle does its own final analysis and zips along
at a smooth 12,000 miles an hour for the hit-to-kill collision.